You're making it out to sound like communities are a bad thing. That MMORPGs, which traditionally are centered around the fact groups of players form lasting communities, is something they shouldn't do...? Like it's not something that should be needed for an MMORPG to last? If that's the case, you're WAY off the mark. Lasting communities have always been what makes a game in this genre hold out for as long as they do. Hell, it's what makes practically anything last as long as it does, regardless of what form of entertainment it is. Its always been about forming bonds with the people around you, where the lone wolf only lasts for so long if they go in not knowing what to expect by doing so.
MMORPGs are always a revolving door, as that's the nature of the genre, something that while not literally unique to it, is more noticeable because you (the player) depend on the existence of other players. Yoshi-P is not wrong to fear that too much change in XIV is a bad thing... it often is in this genre. When you really break it down, the reason you come back to this game is because of the fact you're familiar with it. You know what to expect. You have your online friends, you have your content you're experienced with, you have daily expectations to be met, etc.
Too much of the same thing can be bad, yes, and that is something of concern to folks who notice it. Something to keep in mind though is that bit I mentioned, where MMORPGs are a revolving door of games. They expect you to leave at some point and hope that maybe you'll come back, but it's no skin off their back if you don't because of the simple fact that others will replace you.
No matter what, entertainment always loses appeal sooner or later. Do you still play every game you played 10+ years ago just as much (or more) as you did back then? Hell, do you still play every game you've enjoyed playing in the last few years all the time for each?